在写这篇教程之前，我是连 cmd 都不知道使用的技术小白，在官方文档、技术博客、公司技术同事的帮助下，硬磕了1、2天才从0到1构建了一个ETH网络。以下是我呕心沥血整理的教程，应该是网上最小白的教程了。
1. 下载并安装geth，支持Windows、Mac、Linux、源码
安装包中包含Geth和开发者工具包
• Geth = 以太坊节点进程 + 与区块链交互的命令行客户端 + 密钥管理与签名工具；
• 开发者工具包，包含以下：
安装成功后，在本地指定目录新增以下程序：
安装成功后，geth会自动加入到系统环境变量中，因此可以直接打开Windows CMD输入 geth version，查看版本号，以此证明安装成功。
C:\Users\user>geth version
Geth
Version: 1.9.12-stable
Git Commit: b6f1c8dcc058a936955eb8e5766e2962218924bc
Git Commit Date: 20200316
Architecture: amd64
Protocol Versions: [65 64 63]
Go Version: go1.13.8
Operating System: windows
GOPATH=
GOROOT=C:\go
2. 在启动geth程序之前，先创建以太坊公私钥对，打开Windows cmd， 输入 geth account new , 输入密码，为了安全，输入的密码是不会在cmd上显示出来的， 成功后，钱包地址会显示出来，私钥文件自动存在本地默认目录下，并且再次文字强调要保管好私钥。
C:\Users\user>geth account new
INFO [04-10|17:58:44.410] Maximum peer count ETH=50 LES=0 total=50
Your new account is locked with a password. Please give a password. Do not forget this password.
Password:
Repeat password:
Your new key was generated
Public address of the key: 0xAb4a26Ca4cD52a84d6fc9fb2D7472D2C228742F7
Path of the secret key file: C:\Users\user\AppData\Local\Ethereum\keystore\UTC--2020-04-10T09-58-59.166758700Z--ab4a26ca4cd52a84d6fc9fb2d7472d2c228742f7
- You can share your public address with anyone. Others need it to interact with you.
- You must NEVER share the secret key with anyone! The key controls access to your funds!
- You must BACKUP your key file! Without the key, it's impossible to access account funds!
- You must REMEMBER your password! Without the password, it's impossible to decrypt the key!
可以创建多个公私钥对，私钥都是保存在同一个文件夹中。输入 geth account list，可以将这个文件夹中所有的公私钥对显示出来。
C:\Users\user>geth account list
INFO [04-10|18:27:17.007] Maximum peer count ETH=50 LES=0 total=50
Account #0: {ab4a26ca4cd52a84d6fc9fb2d7472d2c228742f7} keystore://C:\Users\user\AppData\Local\Ethereum\keystore\UTC--2020-04-10T09-58-59.166758700Z--ab4a26ca4cd52a84d6fc9fb2d7472d2c228742f7
Account #1: {820118cd4a04278c773ad30606798d84ce3578e9} keystore://C:\Users\user\AppData\Local\Ethereum\keystore\UTC--2020-04-10T10-25-07.390348400Z--820118cd4a04278c773ad30606798d84ce3578e9
3. 如果需要部署的是私链，可以手动创建创世的json文件，也可以用开发者工具中的puppeth，命令行交互式的完成配置，然后在同级目录下生成一份js文件。支持配置的选项有：链的名字、链ID、POA算法还是POW算法、预充值账户、允许挖矿的账户等，如下：
+-----------------------------------------------------------+
| Welcome to puppeth, your Ethereum private network manager |
| |
| This tool lets you create a new Ethereum network down to |
| the genesis block, bootnodes, miners and ethstats servers |
| without the hassle that it would normally entail. |
| |
| Puppeth uses SSH to dial in to remote servers, and builds |
| its network components out of Docker containers using the |
| docker-compose toolset. |
+-----------------------------------------------------------+
Please specify a network name to administer (no spaces, hyphens or capital letters please)
> myethtestnet
Sweet, you can set this via --network=myethtestnet next time!
�[32mINFO �[0m[04-11|17:01:54.956] Administering Ethereum network �[32mname�[0m=myethtestnet
�[33mWARN �[0m[04-11|17:01:55.141] No previous configurations found �[33mpath�[0m=.puppeth\\myethtestnet
What would you like to do? (default = stats)
1. Show network stats
2. Configure new genesis
3. Track new remote server
4. Deploy network components
> 2
What would you like to do? (default = create)
1. Create new genesis from scratch
2. Import already existing genesis
> 1
Which consensus engine to use? (default = clique)
1. Ethash - proof-of-work
2. Clique - proof-of-authority
> 2
//最好选择POA算法，出块时间固定，ETH最大测试网rinkeby用的就是POA算法
How many seconds should blocks take? (default = 15)
> 5
//设置5秒出个块，对应json文件clique：{"period"}
Which accounts are allowed to seal? (mandatory at least one)
> 0xAb4a26Ca4cD52a84d6fc9fb2D7472D2C228742F7
> 0x820118Cd4a04278c773aD30606798D84cE3578e9
> 0xaFdd64dc5A421cB35ceC78eC991e153045Ca2aB8
> 0x
//一个机器也可以部署多个节点，3个节点基本上可以覆盖全部测试场景
Which accounts should be pre-funded? (advisable at least one)
> 0xAb4a26Ca4cD52a84d6fc9fb2D7472D2C228742F7
> 0x820118Cd4a04278c773aD30606798D84cE3578e9
> 0xaFdd64dc5A421cB35ceC78eC991e153045Ca2aB8
> 0x
Should the precompile-addresses (0x1 .. 0xff) be pre-funded with 1 wei? (advisable yes)
> no
// 如果选 yes，那么从 0x0000000000000000000000000000000000000000 到
// 0x00000000000000000000000000000000000000ff 这些地址都会有 1wei 的以太币。
// 这个看情况选择，用得着就选 yes
Specify your chain/network ID if you want an explicit one (default = random)
>
�[32mINFO �[0m[04-11|17:12:53.755] Configured new genesis block
What would you like to do? (default = stats)
1. Show network stats
2. Manage existing genesis
3. Track new remote server
4. Deploy network components
>
但是 geth 在读取这个配置文件时，只会取到「“genesis”」这个字段，后面的字段不会取到，所以要将 "genesis" 字段的内容作为这个 json 文件的内容（相当于删除{ "genesis":这段字符和文件末尾最后一个}）。
3. 创建节点数据存储的文件夹，并用创世文件初始化节点。创建文件夹可以通过CMD自带的 mkdir 实现，也可以直接在GUI的文件夹下创建。指定节点数据存储位置用 datadir 选项，读取创世配置文件初始化节点用 init 命令。
C:\Users\user>e:
E:\>cd myethtestnet
//我希望节点数据存储在E盘，所以先指定根目录
E:\myethtestnet>geth --datadir ./node1 init ./mygenesis
INFO [04-11|17:39:37.240] Maximum peer count ETH=50 LES=0 total=50
INFO [04-11|17:39:37.687] Allocated cache and file handles database=E:\\myethtestnet\\node1\\geth\\chaindata cache=16.00MiB handles=16
INFO [04-11|17:39:37.807] Writing custom genesis block
INFO [04-11|17:39:37.820] Persisted trie from memory database nodes=4 size=657.00B time=998.4µs gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [04-11|17:39:37.841] Successfully wrote genesis state database=chaindata hash=838c17…ced2bd
INFO [04-11|17:39:37.854] Allocated cache and file handles database=E:\\myethtestnet\\node1\\geth\\lightchaindata cache=16.00MiB handles=16
INFO [04-11|17:39:38.080] Writing custom genesis block
INFO [04-11|17:39:38.088] Persisted trie from memory database nodes=4 size=657.00B time=1.0142ms gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [04-11|17:39:38.110] Successfully wrote genesis state database=lightchaindata hash=838c17…ced2bd
//初始化第一个节点node1
E:\myethtestnet>geth --datadir ./node2 init ./mygenesis
INFO [04-11|17:40:50.190] Maximum peer count ETH=50 LES=0 total=50
INFO [04-11|17:40:50.627] Allocated cache and file handles database=E:\\myethtestnet\\node2\\geth\\chaindata cache=16.00MiB handles=16
INFO [04-11|17:40:50.746] Writing custom genesis block
INFO [04-11|17:40:50.753] Persisted trie from memory database nodes=4 size=657.00B time=999.8µs gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [04-11|17:40:50.765] Successfully wrote genesis state database=chaindata hash=838c17…ced2bd
INFO [04-11|17:40:50.770] Allocated cache and file handles database=E:\\myethtestnet\\node2\\geth\\lightchaindata cache=16.00MiB handles=16
INFO [04-11|17:40:50.879] Writing custom genesis block
INFO [04-11|17:40:50.887] Persisted trie from memory database nodes=4 size=657.00B time=997.8µs gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [04-11|17:40:50.910] Successfully wrote genesis state database=lightchaindata hash=838c17…ced2bd
//初始化第二个节点node2
E:\myethtestnet>geth --datadir ./node3 init ./mygenesis
INFO [04-11|17:41:08.357] Maximum peer count ETH=50 LES=0 total=50
INFO [04-11|17:41:08.781] Allocated cache and file handles database=E:\\myethtestnet\\node3\\geth\\chaindata cache=16.00MiB handles=16
INFO [04-11|17:41:08.937] Writing custom genesis block
INFO [04-11|17:41:08.946] Persisted trie from memory database nodes=4 size=657.00B time=1.0007ms gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [04-11|17:41:08.974] Successfully wrote genesis state database=chaindata hash=838c17…ced2bd
INFO [04-11|17:41:08.989] Allocated cache and file handles database=E:\\myethtestnet\\node3\\geth\\lightchaindata cache=16.00MiB handles=16
INFO [04-11|17:41:09.112] Writing custom genesis block
INFO [04-11|17:41:09.118] Persisted trie from memory database nodes=4 size=657.00B time=0s gcnodes=0 gcsize=0.00B gctime=0s livenodes=1 livesize=0.00B
INFO [04-11|17:41:09.146] Successfully wrote genesis state database=lightchaindata hash=838c17…ced2bd
//初始化第三个节点node3
初始化节点成功后，会在指定目录下增加两个文件夹：
其中 geth/chaindata 中存放的是区块数据，keystore 中存放的是账户数据
4. 配置节点P2P发现网络。新节点要接入P2P网络，至少要发现网络中的一个节点。加入公共网络，直接启动节点即可，因为节点代码中已经写死了boot节点；创建私网，需要用 --networkid="12345" 连接上已知节点；或者将静态节点的地址写到 static-nodes.json 文件中，始终通过静态节点发现网络。我们采用静态节点发现网络的方式，将3个节点的地址全部加到文件中。
先需要知道节点的P2P地址，查询方法，运行geth（记得用 --datadir 指定数据存储位置），运行后按 Ctrl+C 停止运行：
E:\myethtestnet>geth --datadir ./node2
……
……
INFO [04-11|18:20:59.174] Started P2P networking self=enode://c1f667baf27075879900ef48b90c55842c7dfcf2fc63710fdd36955438131087fe259156c0b4595a4fb7ad293b982609ee81edab321f08f61617b02d554dec71@127.0.0.1:30303
在运行过程中输出的log中，有这么一行：enode:……@127.0.0.1:30303。就是该节点的P2P地址，注意P2P地址不是IP地址。
接着创建static-nodes.json 文件，文件名一定要一致，按照以下格式输入三个节点的地址：
[
"enode://f4642fa65af50cfdea8fa7414a5def7bb7991478b768e296f5e4a54e8b995de102e0ceae2e826f293c481b5325f89be6d207b003382e18a8ecba66fbaf6416c0@33.4.2.1:30303",
"enode://pubkey@ip:port"
]
注意，3个节点的端口（port）号不能一样。
注意，一定要将json文件放在节点目录下，如：E:\myethtestnet\node3
5. 启动节点，使用以下命令：
geth --datadir ./node1 --unlock 0 --mine --rpc
geth --datadir ./node2 --unlock 0 --mine --port 30304
geth --datadir ./node3 --unlock 0 --mine --port 30305
--mine，有该选项表示该节点支持挖矿；
--rpc，有该选项表示该节点启动rpc功能，除了第一个节点，其它节点都没有启动 rpc 功能。一是因为 rpc 功能有一个节点启动就够用了；二是因为多个节点启动 rpc 功能，rpc 端口被第一个启动的节点占用，后面的启动就会报失败；
--port，指定了P2P连接的端口，需要与 static-nodes.json 文件中的端口一致，且不同节点不能重复；
节点启动，默认是按照fast节点模式运行。补充说明一下ETH共有三种节点模式：
• Full: Downloads all blocks (including headers, transactions and receipts) and generates the state of the blockchain incrementally by executing every block.
• Fast (Default): Downloads all blocks (including headers, transactions and receipts), verifies all headers, and downloads the state and verifies it against the headers.
• Light: Downloads all block headers, block data, and verifies some randomly.